I agree, it is Latin, not Spanish. I bought my Model 17 and my Model 19 brand spanky new in 1975. They both had the Markas Registradas marking on them. I have several other Smiths with it on them, but I dunno right now exactly when they were made.

I thought this had something to do with ownership of the company by some larger corporation?

I majored in Latin in college and did some graduate work in classical linguistics, which qualified me to do nothing in adult life except (1) teach a couple of dead languages, and (2) answer questions like this.

The word "marca" is not Classical Latin. The word exists in Medieval Latin, where it is a loanword from (probably) a germanic term. The participial form "registrada" is neither classical or medieval Latin, though it has been shaped by rules of Latin word formation. The proper Latin form (if the underlying verb actually existed) would be "registrata," with a t before the final vowel.

"Marca Registrada" is the term for "Trademark" in both Spanish and Portuguese, though the spelling "registada" is also seen in Portuguese-speaking countries. S&W had experienced problems with Spanish knock-offs of their revolvers in the early 1900s; they had also fulfilled two huge contracts to provide weapons to Brazil, a Portuguese-speaking nation, in 1937 and 1946. Roy Jinks has reported that the company found it necessary following an infringement lawsuit in the 1920s to mark their exports to Spain with a Spanish-language trademark to protect their legal rights there. Before WWII, some exported guns were so marked. Shortly after WWII, with the recent 1946 Brazilian contract still visible in the rear view mirror and with the possibility of new international trade opening up in Spanish-speaking countries, president Carl Hellstrom decided to simplify export labeling by just putting the phrase on all company products. It was easier to mark all guns than to keep track of the ones going to specific countries and labeling only those. The order to make the change to the four line address block containing the phrase "marcas registradas" was issued in April of 1948.

S&W wasn't the only company to do this. Am I the only one who remembers the "marca registrada" phrase molded into Coke bottles in the 1950s? I guess there was a body of international copyright law that required imported products to carry trademark notifications in the language of the importing country.

I'm not sure why Brazilian contract guns, all shipped before 1948, don't have the phrase; perhaps the court case had no effect outside of Spain and it is only coincidence that the Spanish phrase is also used in Portuguese.

Spanish is of course one of the Latin based 'romance' languages.
Once I had a Latin-Spanish relapse in a Taco place down on the South side of San Antonio. I wanted to try a variety of tacos in a place where I was the only person there who spoke English. So I just rolled the dice and fired off some numbers from the menu board.
One of my tacos was a lingua taco. That of course is a tongue taco, from the same Latin base from which we get language and similiar words.
That was my only tongue taco. Everybody should try one!

There are taco places in south Texas that have not only tongue, but also brain and eyeball tacos. And maybe even other body parts. There's one large restaurant in Laredo that does an enormous breakfast trade in such "delicacy" tacos and Mariachis (which is the local term for a soft taco). When I lived in Laredo, I took great delight in taking visitors there. But I never ate the tacos.

I think the first 2091 "Mexican Model" .38 targets from 1945-46 were the first with the Latin (or Spanish - take your pick) markings. The 4-line stamping came later. As the intent was to export most of these revolvers to Mexico as a means of getting rid of them, that's why I think Marcas Registradas is Spanish. If you enter Marcas Registradas in Google Translate as being Spanish, it provides the English translation to be "Trademarks." I'm not sure the ancient Romans even had a word for Trademark. If there is, Google Translate does not recognize its having a Latin translation.

I grew up speaking spanish as well, and remember the Coke bottles and other labels thusly marked. Marca registrada is indeed spanish but I'm not at all sure S and W meant it to be. Maybe they intended Latin, or figured it's close enough to latin, spanish and portuguese to work for all three. In any case I'm betting they didn't hire any linguists before they decided to include it.
I like me some tacos de lengua, y de pierna tambien. De ojos, not so much.

If I remember correctly (and I may not), the first use of Marcas Registradas was on ".357" Magnum, Reg. Number 2517, shipped on August 9, 1937 to Roberto A. Gonzales, Mexico City. It was roll marked on the side plate. This Magnum has a 8 1/4-inch barrel and is the only one shipped with Tuskoid stocks.

Now you is talking my talk! I love barbacoa. The other South Texas dish that I like you can't get here is cabrito . Baked baby goat, of course.

And then there's Menudo (tripe stew). You couldn't get it for awhile due to "Mad Cow" prohibitions on eating tripe, but it seems to be back now. At least in South Texas and West Texas, Cabrito is usually roasted on a frame over an open fire. I've never learned to like it. Many Mexican places (the REAL Mexican places, not those frequented by Gringos) usually have Barbacoa and Menudo only on weekends. I've never learned to like those either.

Talk about thread drift. The OP asked a question that could have been answered with a post of 4 digits and we have moved into a linguistic "chicken or egg" dialogue. I'm putting my money on David Wilson.

David, I have jealously acknowledged that you are a statistical "nerd" so I shouldn't be surprised that you are also an erudite etymologist. My Latin consisted of three years of Caesar's Gallic Wars in high school and a graduate level course in Medical Greek and Latin in college. (That last one has been surprisingly helpful throughout my career.) Regrettably, my formal Spanish education only consists of living in Texas for the better part of a century. No matter the original derivation, the meaning of the marking is one of those things that is intuitively known.

Bob

P. S.
Re: tongue. If you haven't tried it, you should. Don't be put off by the papilla. The surface is removed and the tongue is the strongest muscle in the body and very lean. Excellent texture and taste.

Now you is talking my talk! I love barbacoa. The other South Texas dish that I like you can't get here is cabrito . Baked baby goat, of course.

You can get it at my house. I marinate for a few days in olive oil, lemon, garlic and red chile flakes, then spit roast real slow till the meat is falling off the bone. Tortillas for making tacos, cold beer, you're all set.

And then there's Menudo (tripe stew). You couldn't get it for awhile due to "Mad Cow" prohibitions on eating tripe, but it seems to be back now. At least in South Texas and West Texas, Cabrito is usually roasted on a frame over an open fire. I've never learned to like it. Many Mexican places (the REAL Mexican places, not those frequented by Gringos) usually have Barbacoa and Menudo only on weekends. I've never learned to like those either.

Love menudo. Best thing ever for "crudo" - hangover, and puts chicken soup to shame for a cold or the flu. Traditionally the broth should be made from beef feet. The meat under the hoof is the softest and most tender part of the animal. But what a stench while it's simmering all day.

Back in post# 14, David Wilson mentions the post WWII Brazilian guns that don't have the "Marcas Registradas" stamp. Those guns were built on left over WWI frames that were probably already stamped with period markings, which did not include the trade mark info.

Love menudo. Best thing ever for "crudo" - hangover, and puts chicken soup to shame for a cold or the flu. Traditionally the broth should be made from beef feet. The meat under the hoof is the softest and most tender part of the animal. But what a stench while it's simmering all day.

The best chicken soup was made from the feet.
To seven year old me, the cooked feet tasted good -- cold with ketchup.
It took a lot of work to get the meat from between the tendons.
Yum.